Clamp for electric metal-working apparatus.



G. B. BARSIQZ i i I CLAMP FOR ELECTRIC METAL WORKING APPARATUS.

' nrmouzon rnnn JUNE 10, 19 1.

Patnted Feb. 11, 1913.

a sums-sunny nwmro MIG/966 EvBIIFgT'ZIM ITTORIJEVS G.,E. BARSTOW. CLAMP FOR ELECTRIC METAL WORKING APPARATUS.

' APPLIOATION FILED JUNE 10, 1911. 1,052,787.

I Patented Feb. 11,1913.

3 SHEETS-11113?! 2.

[WEI/T08 GEORGE E.B4R3TOW.

arm/Mrs 'G. E. BARSTOW. CLAMP FOR ELECTRIC METAL WORKING APPARATUS. APPLI 0ATION FILED JUNEIO, 1911.

. 3 SHEETS-SHEET 3 INVENTO GEORGE E. El TOM Arron/m8 Patented Feb. 11, 1913.

UNITED stra'rns anus @FFIQ.

GEORGE E. BARSTOW, OF LYNN, MASSACHUSETTS, ASSIGNOR TO THOMSON ELECTRIC WELDING COMPANY, OF LYNN, MASSACHUSETTS, A CORPORATION OF MASSACHU- SETTS.

Specification of Letters Patent.

CLAMP FOR ELECTRIC METAL-XVORKING AIPARATUS.

, Patented Feb. 11,1913.

Application filed June 10,1911. Serial No. 632,368.

To all whom it may concern:

Be it known that I. GEORGE E. Bans'row, a'

citizen of the United States, and a resident of Lynn, in the'county of Essex and State of Massachusetts, have invented certain new and v useful Improvements in Clamps for Electric Metal -\Vorking lip giaratus of which the following is a specification.

My invention relates to work-clamping mechanism for electric metal working apparatus and is designed to cause the work to heat uniformly across its width.

In electric metal Working apparatus, more noticeably when operating on wide stock, the part'of the work farthest from the primary coil of the transformer takes the longest and is the hardest wheat and therefore considerable diii lcult-y is experienced in heating uniformly across the line of weld or part to be otherwise worked especially in the case of wide stock when positioned vertically in the machine.

In accordance with this invention. the

,i above referred to diiliculty is overcome by varying the biting, etiect or the pressure of the clamping jaw on the stock to be welded or otherwise worked, the clamping" ja-w forming a contact for feeding current to the work. By causing, the clamping jaw to bite harder or apply an increased pressure at the part of the stock remote from the primary coil, the current-will flow more readily through the work at the point of greatest pressure and the section of work will heat more uniformly.

The invention consists in the improved clamp for electric metal workingapparatus hereinafter described and set forth in the claims.

The invent-ion also consists in the details of construction and combinations of parts hereinafter more particularly described and jaws. Fig. 5 is a similar view to Fig. l showing he clampingjaws 1n unclamped position after release of the work.

In the drawings the usual platens or supports for the work-clamping mechanism are indicated at 1, 1. These platens work in the usual way upon any proper guides on the frame or table of the machine and are connected to a source of electric energy such, for instance, as the flexible secondary 2 of atransformer in a manner well known in the artand which need not be here described in detail.

Either one or both platens may be movable in their guides by any sui able means to apply welding or upsetting 1.1.r8SSlllt-3 to the heated section of the work by any of the means now well known to those skilled in the electric metal working art. Such well known means it is not necessary to show or further describe in. detail as they form 110 part of "the present invention.

Both platens being duplicates as regards the work-clamping mechanism carried thereby, a description of one will sutlice for both, it being understood that the work clamping mechanism on each platen grips the work either side of the line of desired weld 4 indicates a freely mounted slide mounted in guides 5 and movable transversely of the platen 1 to cause it to travel toward and away from the fixed clamping jaw The slide i carries on its inner end a clamping jaw 6 pivot-ally mounted on a projection or stud 7 extending from the side of the slide H j 8 indicates a clamping lever pivotally mounted in a bracket- 9 secured to the platen and provided with a. cam 10 which engages the rear end of the slide 4 and in one direction of rotation causes the jaw 6 to be moved toward the jaw When the cam 10 is rotated in the reverse direction, by means of the lever 8. the slide 4 is retracted by means of a. pin 11 project-in from the side of the c:.m l0, and carried thereby, engaging a hook 12 secured to the slide e and the jaw 6 is consequently drawn away from the jaw 3.

into the pocket leiam 1 and the clamp open, a sprin til trative head 16 by mcans of which the end of the rod 13 is caused to pro ect a greater or less extent into the pocket 14-. The clamping jaw 6 provided with an arm 17 projectirm n. such position that it will strike the end of the rod 13 when the jaw has traveled a sufiicicntdistance as Wlll be hereinafter described.

llori'nally when the slide 4 is retracted 18, compressed between ledge 1?) secured to the arm 17 and the slide -l-, tips or rocks the jaw 6 until ts mwement is stopped by a pin 20 secured I Q slide 4:5

Y be clamping lever 8, the arm 17 f tribes the projecting end of the tiesor rock. the ja and causes diners or less depen ing on the amount the end of the rod 13 projects and therefore the points during the travel of the slide i that it strikes the arm 17. v T

c as follows: t at is welded i the illusa iwtang'ular section teed beti vecn the its 3 'noin 8 brought for i s t aw 6 to travel is slide and at a predeteu m 1? SlilllES the end of b. fur 1 51 movement auses .i c uppe" end of-the the upper i operation oi: "the de l; )eratcd orward anc grin .oru with. more or less pressure osi of t e end of the rod loo.

or pressure desireclass i can be made to t the jaw 6 and so lDCIQ SVJ or c reuse the i of work 7 1a clamps for this the 6 was rigidly secured '5 as the clamping pressure was apwas sullicicnt to take the pressure oi? e up" part of the worlc and apply it at the lower Pt whereby sati actory heating could i coerce? with this iny has Jeen successfully It will understood that my invention is not limited to the deli -is of construction shown and described, llllu same being; illusonly, but modifications ll us departures and. ted to without the invention departing Lei-lung; apps a clampu: 11

Vi licn the jaw is moved for-r wde 4t and the tendency of tlie-slidei .taincd. 13y rue construction.

tus, the combination of assays? and means acting on said jaw to automatically vary the clamping pressure on different parts of the work.

2.1m an electric metal working apparatus, the combination of a pivotally mounted clamping jaw and means for automatically rocking said jaw to vary the clamping pressure on different parts 1 the work. i,

3. In an. electric metal working apparatus, the combination of a pivotally mounted clamping jaw movable bodily to engage the work and means for automatically rock'- ing said jaw in a predetermined point in its movementto adjust the clamping pressure on the work.

4 In an electric metal working apparatoss, the combination. of a pivotally mounted cramping jaw and adjustable means adapted to automatically rock said jaw to adjust the clamping pressure on difi'erent parts of the work.

5. In an electric metal tus, the combination of a slide, a clamping jaw pivotally mounted on said slide and means independent of the work and adapted to automatically rock said jaw to adjust; the clamping pressure on the worlr 6. In an electric metal working apparatus, the combination of a slide movable transversely to the work, a clamping jaw carried by said slide and means acting on said jaw at a predetermined point in the rival of said slide and adapted to adjust the pressure of said jaw on different parts of the work.

'7. in an electric metal working apparatus the combination of a slide, a pivotally mounted clamping jaw carried thereby and an adjustable stop adapted to strike said. at a predetermined point in the travel of said slide whereby further movement of the slide will cause said jaw to be rocked about its pivot asvand for the purpose described.

8. In an electric metal working apparatus, the combination of a fixed clamping jaw, a laterally movable clamping jaw and an adjustable stop adapted to rock said movable jaw at a predetermined point in its movement as and for the purpose described.

9. In an electric metal working apparaa fixed clamping jaw. a slide movable laterally to the work, a pivotally mounted clamping jaw carried by s l slide, a stop located in the path of travel of said jaw to rock the same at a predcterminedpoint in its movement and means for adjusting the position of said stop.

10. .ln an electric metal workin apparatus, the combination of fixed and movable clamping jaws adapted to supply current to the work a pivotal mounting for one of said jaws and means adapted to Vary the working apparaclamping pressure of said jaws on different parts of the Work by swinging said jaw about its pivot.

11. In an electric metal working apparatus, the combination of fixed and movable clamping jaws adapted to supply current to the work and means adapted to automati sally vary the clamping pressure of said jaws on different parts of the same section GEORGE E. BARSTOW. \Vitnesses:

GEO. W. N. CIIADWELL, JAMES F. DEARBORN. 

